Eclipse

As much as I hate to sound like Nick Burns (your company's computer guy), and not that i matters, but a lunar eclipse is actually when the earth eclipses the moon (this occurs at night). The eclipse you described is called a solar eclipse (this occurs during the day). The moon's angular size is significantly smaller than the sun's, from the earth, so the moon can never complety eclipse the sun. Looking directly at a solar eclipse is not a good idea. All you see is the sun with a small black circle over it which is of course the moon. For some reason you're not supposed to look directly at the sun. If you were to look you would not be looking at the dark side of the moon, you'd be looking at the same side of the moon that you always see. Only now it's complety dark as it is once every 30 days of so. The moon is never light as a result of light reflecting from the earth. Half the moon is always light as a result of the sun, this half changes as the moon's position changes relative to the sun. The reason the moon has phases is a certain portion of the light half of the moon is visible from earth. As stated in my earlier post, what we refer to as the dark side of the moon (the side we never see), get as much light as the side we see. We never see it because its always facing away from the earth, not because it doesn't get light. Hope this clarifies the astromony :)

Now that I'm done boring the hell out of everyone, I would say that DSOTM has nothing to do with insanity. Waters is simply using sarcasm. He's insulting the idea of people being considered "luney" for not following all of society's conventions. The moon represents common sense and basic instincts that all of us have, and the sun is what we have been trained to do and how we have been trained to act. Everything will be in "tune" when you listen to your basic instincts, as opposed to the conventions you've been taught.